Enjoy the eclipse and keep your vision healthy with the right eye protection.
If you’ve ever gotten a sunburn after spending time outside, you know how powerful the sun’s rays can be. And if you’ve squinted or worn sunglasses on a sunny day, you can imagine the kind of effect that those rays can have on the delicate structures of your eyes. (That’s one reason that Heritage recommends investing in a good pair of sunglasses for your long-term eye health.)
A total solar eclipse, where the moon crosses in front of the sun and fully blocks it, is due to occur in the skies above the US on April 8th. Eclipses are rare, dramatic events, and many people will head outside next week to catch a glimpse. But eclipses also present some unique risks to your vision, and it’s critical for your health to know how to watch one safely.
You’ve probably heard that you shouldn’t look at the sun during an eclipse, and that’s true. But that doesn’t mean there’s no way to enjoy this one-of-a-kind event. In this article, we’ll explain why eclipses can be dangerous for your eyes, what you should watch out for, and how to protect yourself as you do a little sky-watching.
The sun may be less bright, but it can still burn
During a solar eclipse, the moon crosses between the sun and the earth, blocking part or all of the sun, depending on where we’re standing to see it. A partial solar eclipse, also called an annular eclipse, is when the moon only covers a portion of the sun. In a total eclipse, the entire disk of the sun is covered by the moon.
When the moon is in front of the sun, it blocks out a portion of the sun’s light, making the day outside appear darker. This can make it more tempting to sneak a peek at the eclipse. It’s interesting to look at, but it’s also easier to see, because your body doesn’t have the same instinct to squint or close your eyes that it does when you experience the sun’s full brightness. But it’s important to know that looking at the sun during a partial eclipse causes the same damage as looking into the unblocked sun.
Even when the moon is mostly covering the sun, the sun’s intense rays still reach us around the edges of the moon, and they’re enough to cause damage to our eyes. Our retinas—the sensitive membranes at the back of the eye that send visual input to the brain—don’t feel pain, so you wouldn’t know that the damage was occurring until later, when symptoms appear.
That’s why you should never look directly at the sun during an eclipse. Below, we’ll tell you more about filters and other viewing options that can help you watch the eclipse safely. The only exception to this rule is during “totality,” the one to two minutes during a total eclipse (not a partial one) where the sun is fully covered by the moon. Then, it’s safe to admire the view—but be sure to protect your eyes again before the moon moves away.
Retinal injury can cause permanent blindness
Even a brief exposure to the sun’s rays can cause damage to your retina. The resulting condition is called “solar retinopathy.” Symptoms include blurry or reduced vision, sensitivity to light, color disturbances, and spots in your vision that don’t go away. In most cases, these symptoms resolve over time—usually a month or two, but potentially as long as a year. However, in some cases, the damage can be permanent.
If you notice symptoms of solar retinopathy after viewing the eclipse, be sure to get your eyes checked right away. Your care provider can take a close look at your retina to assess the damage, and help you manage your symptoms. Currently, there is no established treatment for solar retinopathy, though—it’s just a question of waiting for your eyes to heal on their own.
Use rated filters or viewers for safety—and take care with technology
Fortunately, we have tools to let us watch the eclipse without putting our eyes at risk. The simplest and most common are probably eclipse glasses: eye protection with lenses that are filtered and darkened to keep out the sun’s harmful rays. Sunglasses, even very dark ones, are not enough.
Solar viewers have to meet international standard ISO 12312-2 in order to be safe for use, so homemade filters won’t cut it, either. If you purchase eclipse glasses, be sure to get them from a reputable provider—the American Astronomical Society has a list of suppliers on their webpage. And, like with any eye protection, be sure to inspect your viewers before you put them on. If they’re damaged, don’t use them.
If you prefer to watch the eclipse in a less direct way, you can look into creating a pinhole viewer. These can be as simple as a wooden spoon with holes in it, but a slightly fancier version, using cardboard and aluminum foil, can be a fun project to do with kids.
Telescopes, binoculars, and other optical magnifiers also require specialized filters—because of the way they focus and enhance the sun’s rays, regular eclipse glasses aren’t strong enough to protect your eyes. If you’d like to see a magnified view of the eclipse, be sure to check with an expert on the right kind of filter to keep your vision safe. You might also be tempted to try and watch the eclipse through your phone camera, but it’s not recommended—the sun is intense enough to damage the sensor on a digital camera, too.
Eclipses are rare, but your eye health affects you every day.
Taking care of your vision is an ongoing task. Eating right, exercising, and taking advantage of your regular eye exams all contribute to your long-term eye health. And so does wearing eye protection, whenever the situation calls for it.
On April 8th, if you’re able to, get outside and enjoy the eclipse—just make sure you take the right precautions first. And if you have any questions or concerns about the health of your eyes, sun-related or not, ask your care provider about them at your next eye exam. To find a care provider in your area, use Heritage’s provider search tool, or contact us today.